Animal Biology Fundamentals: Cells, Tissues, and Systems
Animal Biology Fundamentals: Eukaryotic Cells
Nucleus: Holds genetic material. Protected by a double membrane that separates it from the cytoplasm.
Vacuoles: Small sacs that store various substances.
Lysosomes: Produced by the Golgi apparatus; responsible for digesting materials inside the cell.
SER (Smooth Endoplasmic Reticulum): Produces lipids and aids in detoxification (removal of toxic substances).
Mitochondria: Have two membranes; break down glucose to release energy via cellular respiration.
Cytoplasm:
Fundamental Concepts of Biology: From Cells to Ecosystems
Characteristics of Living Organisms
- Sensitivity
- Organisms respond to diverse stimuli.
- Adaptation
- All living organisms exhibit a “fit” to their environment.
- Metabolism
- This refers to the chemical reactions that occur within living organisms to maintain life.
- Homeostasis
- The ability of an organism to maintain constant internal conditions.
- Organization / Order
- Organisms are highly organized structures. The cell is the basic unit of life.
Levels of Biological Organization
- Population
- A group of organisms of the
Milestones in Genetics: History, Concepts, and Disorders
Key Historical Discoveries in Genetics (8000 B.C. – 1962)
| Year | Discovery / Event | Scientist(s) Involved |
|---|---|---|
| 8000–1000 B.C. | Humans knew sexual reproduction caused variation (used in selective breeding). | Ancient humans |
| 1856–1863 | Hybridization experiments on garden peas (basis of inheritance laws). | Gregor Johann Mendel |
| 1865 | Publication of Mendel’s work, “Experiments on Plant Hybridization”. | Mendel |
| 1866 | First description of Down Syndrome. | Langdon Down |
| 1891 | Discovery of the X-body (X chromosome) during spermatogenesis |
Viral Immunity and Pathogenesis: Host Defense Mechanisms and Infection Outcomes
Host Defense Mechanisms Against Viruses
Innate, Intrinsic, and Adaptive Immunity
- Innate Immunity: Non-specific, immediate response. Uses Pattern Recognition Receptors (PRRs) to detect Pathogen-Associated Molecular Patterns (PAMPs).
- Intrinsic Immunity: Always present in cells (pre-existing defenses).
- Examples: TRIM proteins, MxA, Tetherin, autophagy, apoptosis.
- Adaptive Immunity: Specific, develops after infection.
- Two arms: T cells (cell-mediated) and B cells (antibody-mediated/humoral).
Pathogen-Associated
Read MoreComparative Adaptations for Respiratory Gas Exchange
The Process of Gas Exchange
Gas exchange is the vital physiological process by which oxygen ($ ext{O}_2$) from the environment is taken into the body and carbon dioxide ($ ext{CO}_2$), a waste product of cellular respiration, is removed. In animals, this process typically occurs across specialized respiratory surfaces, such as:
- Lungs (mammals, birds, reptiles)
- Gills (fish, some amphibians)
- Skin (some amphibians, invertebrates)
Oxygen diffuses across thin, moist membranes into the bloodstream or directly
Read MoreMolecular Genetics: Key Concepts and Mutation Effects
Molecular Genetics Fundamentals
Cellular Transformation and Key Enzymes
Transformation studies demonstrate the ability to transition from non-disease-causing to disease-causing states, often involving the uptake of genetic material.
Enzyme Definitions
- Enzyme that degrades DNA: DNase
- Enzyme that degrades protein: Protease
- Enzyme that degrades RNA: RNase
Cell Types and Ploidy
- Somatic Cells: Non-reproductive cells (diploid).
- Gametes: Reproductive cells (haploid), containing half the amount of DNA as somatic